Regenerative medicine: then and now--an update of recent history into future possibilities

Abstract

The fields of tissue engineering (TE) and regenerative medicine (RegMed) are yet to bring about the anticipated therapeutic revolution. After two decades of extremely high expectations and often disappointing returns both in the medical as well as in the financial arena, this scientific field reflects the sense of a new era and suggests the feeling of making a fresh start although many scientists are probably seeking reorientation. Much of research was industry driven, so that especially in the aftermath of the recent financial meltdown in the last 2 years we have witnessed a biotech asset yard sale. Despite any monetary shortcomings, from a technological point of view there have been great leaps that are yet to find their way to the patient. RegMed is definitely bound to play a major role in our life because it embodies one of the primordial dreams of mankind, such as: everlasting youth, flying, remote communication and setting foot on the moon. The Journal of Cellular and Molecular Medicine has been at the frontier of these developments in TE and RegMed from its beginning and reflects recent scientific advances in both fields. Therefore this review tries to look at RegMed through the keyhole of history which might just be like looking 'back to the future'.

Fig 1

The myth of the Titan Prometheus provides an icon for RegMed. Prometheus was known as the benefactor of mankind for his desire to assist mortals and give them many beneficial gifts that helped them to survive and live prosperous lives. His duty as a god was to form man from water and earth, and in doing so, gave them each a gift of strength or speed, craftiness or wisdom, and many other benefactors that improved their ways of living. The most well-known gift of Prometheus was the gift of fire which Prometheus stole from Zeus’ lightning bolts. Prometheus’ defiance and betrayal provoked Zeus to have him chained to Mount Caucasus, where an eagle ate daily from his ever-regenerating liver. As an immortal Titan, Prometheus’ liver grew by night what the eagle had eaten the day before. His torture lasted 30,000 years until he was freed by Hercules.

Fig 2

Scanning electron microscopy of a microvascular corrosion cast. This is a replica of a neovascular network created by means of an arteriovenous loop in the rat model under influence of VEGF(165). On the left side an overview demonstrating a relative nascent network (2 weeks after creation of the loop) with numerous new capillaries demonstrating different stages of arborization and remodelling. (a) Loop formation by means of intercapillary bridging. (b) Intussuceptive (non-sprouting) angiogenesis with intervascular division. This is a particularly energy saving modus of angiogenesis and remodelling. (c) Neovascular sprouts (sprouting angiogenesis) are seen all around the picture, demonstrating a vivid ongoing angiogenesis.

Fig 3

The ‘Gartner Hype Cycle’ for new technological advances in regard to financial and business considerations.

Fig 4

Digitally coloured transmission electron micrographs of mouse heart show telocytes (TC) in blue. (A) Cardiac structural unit composed by cardiomyocyte (CM), blood vessel and TC. Telocyte extends its characteristic, very long and thin, process (Tp-telopode) between arteriole and cardiomyocyte. (B) Regenerative cardiac unit composed by cardiomyocyte progenitor (CMP), capillary (cap), nerve and TC.